Ceramic pigment and method of manufacture of same



Patented July 7,1953 I 2,644,767;

UNITED am ss I CERAMIC PIGMENT ANDIMETHOD F MANUFACTURE OFV'SAME I Russell F. Duncan, Bel-ea, Ohio, assignor tolFerro,

Corporation, a corporation 9f, Ohio No Drawing. Application May 18, 1950, Serial'No. 162,801;

3 Claims. (01. 106 -292) This invention is a continuation in-part of my pigment in which the major pigmentation is proco-pending application Serial Number 67,749, vided by compounds of cobalt in combination with filed December 28, 1948, and now abandoned. compounds of aluminum, calcium, zinc, or silica This invention relates to a pigment of thecoand in whichincreased pigmenting value is obbalt alumina type having enhanced pigmenting 5 tained by the addition of minor amounts of comal pounds of molybdenum. 1 Calcines of cobalt and alumina are well known While in its preferred embodiment y invenforms of commercial blue pigment which has an lZiOn comprises the use Of cobalt in combination improved pigmenting value. with alumina, zinc, and silica various combina- It is of the utmost importance to note that in;l0 tions o he e m s wit or without the the pigmenting of ceramic materials, for which alumin m y be used. The characterizing elethis invention is particularly adapted, there are m t f t pi m nt f th 'p sent inv nti n, two general types of pigmenting materials. First, molybdenum, has b tried n C ju ction With there are vitrifiable materials, such as the glazes, Cobalt and Zinc, cobalt, and ealeium, eebalt d for use on glass and second, th are t m. silica, and various other combinations of cobalt vitrifiable pigments hi h are d of mm and the above mentioned elements; the results ti t very high temperatures Th Second class obtained definitely show that while each of such of pigmenting material while not in themselves blues was improved by t u of y d num,

vitrifiable can be and are used to pigment vitrithey w s ill n t as desirable as the l pi fiable materia1s ments made from cobalt, alumina, zinc, silica and In developing glazes for use on glass the manumolybdenum s facturer is confronted with the problems of melt- The compounds of Cobalt alumina, Zine, ca

ing point, gloss, hemic l r i ta d th as well as the molybdenum which characterizes proper coeflicient of expansion. To meet these the improved pigment Of my ti n may be conditions it is necessary to put together a compresent in the final composition i y f the ple compound s materials as lead boron variety of forms in which elements such as those l i soda potash silica, comring mentionedcommonly occur in compositions of t p t are mixed in t proper proportions this character. From the standpoint of facility and lt t a glassy t t The resultant of manufacture, low cost of production and genglass is a very complex material which has under- Grill superielty results Obtained, the fi e e r gone extremely complex chemical changes tioned elements will be present in the form which While the non-vitrifiable pigmenting materials esults from the eeleinatien of t e oxides of these r i th l complex chemical compounds elements. It is to be understood, however, that they do not have the physical properties of glazes. instead of using the y e bearing forms these It is also important to note that the non-vitrifiaelemsnts may be added o t new mix, before ble pigments can be used to color glazes but in calcihationi in 1he form f Such p unds therethemselves cannot be used directly as glazes of as will,.as a result of the calcination step, yield These materials are prepared by intimately mixcompositmn Comparable to that ed by the ing the raw materials and then calcining at very use Of the Oxygen bearing o ms.

high temperatures on the order of 2000 to 40 In r p ri my imp ov pi m n he pre- 28000 ferred proportions used are black cobalt oxide It is therefore a principal object of my inven- 20-40 parts by Weight aluminum oxide, 40-70 tion to provide a composition and method of parts by Weight, Zinc Oxide Parts by Weight manufacture of a ceramic pigment which will re- F parts by Weight and molybdenum sult in a product of greater pigmenting value. oxide parts byweight a It is a further object of this invention to pro- AS an example of a blue Yplgment the vide a ceramic pigment for coloring, vitrifiable preferred range, the following example is given: ceramic materials. Black cobalt oxide lbs. 34.1 Other objects of the invention will appear as Aluminum oxide lbs. 58.0 the description proceeds. Zinc oxide lbs. 2.96 To the accomplishment of the foregoing and Silica lbs. 2.96 related ends, the invention, then, comprises the Molybdenum trioxide lbs. 1.98 features heremafter fully descnbed and This formulation was intimately wet mixed for ticularly pointed out in the claims, the following a description setting forth in detail certain illus- 3: 22: 2??? g gbijo gigfi gxg gag z igf Z 5? trative embodiments of the invention, these bemg the calcined mass was wet i milled until ing indicative, however, of but a few of the ways th ground m t rial passed 100% through a 325 in which the p p e O e invention y be mesh sieve. After grinding the material was employed. dried in a hot air oven and then pulverized in a Broadly stated this invention comprises a blue suitable pulverizer.

The finished product was a clean bright blue with an exceptionally high pigmenting value.

The product of my invention is a strong color, cheap to manufacture, has very good weathering properties and is chemically durable. Due to these properties the product of my invention has been found to be particularly desirable in the manufacture of roofing granules. The product of this invention can also be used in the pigmentation of plastics, printing inks, paint and rubber.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

1', therefore, particularly point out and distinctly claim as my invention:

1. The process of making a ceramic pigment which comprises intimately mixing black cobalt oxide from 20-40 parts by weight, aluminum oxide from 40-70 parts by weight, zinc oxide 1-5 parts by weight, silica 1-5 parts'by weight and molybdenum trioxide 0.5-10 parts by weight, calcining the mixture in a furnace at a temperature of 2000-2350 R, for about 5-6 hours, wet

milling the resultant cooled calcined mass, drying and then pulverizing in a suitable pulverizer.

2. The process of making a blue ceramic pigment which comprises intimately mixing 34.1 lbs. of black cobalt oxide, 58.0 lbs. of aluminum oxide, 2.96 lbs. of zinc oxide, 2.96 lbs. of silica and 1.98 lbs. of molybdenum trioxide, calcining the mixture at a temperature of about 2000-2350 F. for about 5-6 hours and grinding the resultant product for addition of roofing granules.

3. A calcined blue ceramic pigment as produced by the process of claim 1.

RUSSELL F. DUNCAN.

References Cited in the file of this patent Vitrifiable Colors for Decorating Glassware, Dougherty Journal American Society, vol. 1'7, June 1934, page 1'79.

Hackhs Chemical Dictionary, Ingo W. D. Hackh and Julius Grant, second edition, P. Blakistons and Co. Inc., Philadelphia, Pa., 1937, col. 2, page 602.

Uses and Application of Chemicals and Related Materials, Gregory, vol. 1, Reinhold Publishing Corp., New York, 1939, page 393. 

1. THE PROCESS OF MAKING A CERAMIC PIGMENT WHICH COMPRISES INTIMATELY MIXING BLACK COBALT OXIDE FROM 20-40 PARTS BY WEIGHT, ALUMINUM OXIDE FROM 40-70 PARTS BY WEIGHT, ZINC OXIDE 1-5 PARTS BY WEIGHT, SILICA 1-5 PARTS BY WEIGHT AND MOLYBDENUM TRIOXIDE 0.5-10 PARTS BY WEIGHT, CALCINING THE MIXTURE IN A FURNACE AT A TEMPERATURE OF 2000-2350* F., FOR ABOUT 5-6 HOURS, WET MILLING THE RESULTANT COOLED CALCINED MASS, DRYING AND THEN PULVERIZING IN A SUITABLE PULVERIZER. 